just ran across this. pretty interesting info. i'd kill to see the actual curves for serum T after the single daily oral T dose! steep slope, you think?
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Oral testosterone in oil: pharmacokinetic effects of 5alpha reduction by finasteride or dutasteride and food intake in men.Amory JK, Page ST, Bremner WJ.
University of Washington, Box 356429, 1959 NE Pacific St, Seattle, WA 98195, USA. jamory@u.washington.edu

Oral administration of 400 mg of testosterone (T) in oil, when combined with the 5alpha reductase inhibitor dutasteride (D), elevates serum T in medically castrated men to the normal range. In this study, we sought to determine the impact of 1) finasteride (F) and 2) food intake on the serum T and dihydrotestosterone (DHT) levels observed after the oral administration of T in oil. Therefore, we conducted a pharmacokinetic study of oral T in oil, alone or with D or F, in the fasting and fed states in normal men whose endogenous T production was suppressed by the GnRH antagonist acyline. After acyline administration, 7 healthy men (mean age 31 +/- 8 years) were sequentially administered five 400-mg doses of oral T in sesame oil once daily. The first dose of oral T (T-alone) in oil was given while fasting without F or D. The second (fasting) and third (fed) doses were administered after pretreatment with F (T + F). Four days later, the fourth (fasting) and fifth (fed) doses were administered after pretreatment with D (T + D). Blood samples for measurement of serum T and DHT were obtained before T dosing and 0.5, 1, 2, 3, 4, 6, 8, 10, 12, and 24 hours after each administration. In the fasting state, 24-hour area-under-the-curve of serum T after oral T administration was significantly greater with coadministration of either D or F compared with T-alone (126 +/- 36 nmol-h/L [T-alone] vs 287 +/- 98 nmol-h/L [T + F] vs 236 +/- 82 nmol-h/L [T + D]; P < .05 for T + F and T + D vs T-alone). Administration of the T with food nonsignificantly decreased serum T levels compared with fasting administration. The administration of oral T in oil combined with either F or D results in serum T levels adequate to treat men with testicular failure. Additional studies of the combination of oral T in oil with 5alpha-reductase inhibitors as a novel form of oral T therapy are warranted.

PMID: 16400081 [PubMed - indexed for MEDLINE]

**** another one, similar outcome *****

Oral testosterone in oil plus dutasteride in men: a pharmacokinetic study.Amory JK, Bremner WJ.
Center for Research in Reproduction and Contraception, Division of General Internal Medicine, University of Washington Medical School, Box 356429, 1959 NE Pacific Street, Seattle, Washington 98195, USA. jamory@u.washington.edu

Testosterone (T) is not administered orally, because it has been reported to be rapidly metabolized by the liver. We hypothesized that sufficient doses of T or T enanthate (TE), administered orally in oil, would result in clinically useful elevations in serum T. We also hypothesized that coadministration of dutasteride (D) with T or TE would minimize increases in serum DHT seen previously with oral administration. Therefore, we conducted a pharmacokinetic study of oral T and TE in oil, with and without concomitant D, in normal men whose T production had been temporarily suppressed by the GnRH antagonist acyline. Thirteen healthy men (mean age, 24 +/- 6 yr) were enrolled and assigned to oral T (n = 7) and oral TE (n = 6) groups and were administered 200, 400, or 800 mg of either T or TE in sesame oil in the morning on 3 successive days 24 h after receiving acyline. Blood samples for measurement of serum T and dihydrotestosterone were obtained before T or TE administration and 0.5, 1, 2, 4, 6, 8, 10, 12, and 24 h after administration. Subjects were then administered D for 4 d before repeating the sequence of T or TE doses with D. Serum T was significantly increased in a dose-dependent fashion with the administration of oral T or TE in oil. Coadministration of D with oral T or TE significantly increased the 24-hr average serum T levels compared with administration of T or TE alone [average serum T after 400 mg dose, 8.7 +/- 3.0 nmol/l (T) and 8.3 +/- 5.7 nmol/l (TE) vs. 16.1 +/- 5.8 nmol/l (T +D) and 15.0 +/- 8.8 nmol/l (TE + D); P < 0.05 for T vs. T and D]. The administration of oral T or TE in oil combined with D results in unexpected and potentially therapeutic increases in serum T. Additional studies of this combination as a novel form of oral androgen therapy are warranted.

PMID: 15713724 [PubMed - indexed for MEDLINE]

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can anyone convert those nmol/l figures to ng/dL?